[R] Automatically fix big jumps in one variable due to anomalies

[PIKAL Petr]

Hi

Not sure if it solves all possible misbehavior with sensor but
changing all jumps start to NA or 0, summing diferences and adding them to start can help you to polish your data

> x
 [1]   NA   NA  246  251  250  255 5987 5991 5994 5999
xd<-diff(x)
xd[xd>10]<-NA
xd[is.na(xd)]<-0
> cumsum(xd)
[1]  0  0  5  4  9  9 13 16 21
> 246+cumsum(xd)
[1] 246 246 251 250 255 255 259 262 267

Regards
Petr

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Cesar Terrer
> Sent: Tuesday, March 05, 2013 12:13 AM
> To: r-help at r-project.org
> Subject: [R] Automatically fix big jumps in one variable due to
> anomalies
> 
> Hi,
> I am attaching a plot where you can see there are a few "jumps" (plots
> 1, 4,
> 5 and 6), due to incidents with the measuring sensors (basically
> someone touching the sensor). I need to revert those changes to have a
> plot without unreal measurements, so make those fragments go back to
> its original pattern before the jump.
> 
> I have used the function cpt.mean {changepoints} so I can identify the
> jumps and the mean of each segment. Now I don't know how to
> automatically revert the jumps, probably subtracting one higher
> fragment mean by the mean of the previous one. Does it make sense?
> 
> Example of data set
> 
>                 TIMESTAMP          variable   diameter
> 38  2012-06-21 13:45:00     r4_3       NA
> 86  2012-06-21 14:00:00     r4_3       NA
> 134 2012-06-21 14:15:00     r4_3       246
> 182 2012-06-21 14:30:00     r4_3       251
> 230 2012-06-21 14:45:00     r4_3       250
> 278 2012-06-21 15:00:00     r4_3       255
> 326 2012-06-21 15:15:00     r4_3       5987
> 374 2012-06-21 15:30:00     r4_3       5991
> 422 2012-06-21 15:45:00     r4_3       5994
> 470 2012-06-21 16:00:00     r4_3       5999
> 
> As an example, this is the current diameter data:
> NA-NA-246-251-250-255-5987-5991-5994-599
> 
> I would need this series without the big jump, avoiding the jump and
> following the increase/decrease pattern, for example:
> NA-NA-246-251-250-255-255-259-262-267
> 
> Any other idea is welcome.
> 
>